Update README.md for Textual 3.0.1

With Textual 3.0.1, scripts aught to be in the ~/Library/Application Scripts/<bundle> directory. Effective as of https://github.com/Codeux/Textual/commit/4a93fb1fadd1005332b36126e87317c828c5f90f
Merge pull request #1 from demosdemon/patch-1

Update README.md for Textual 3.0.1